Method for reducing kinetic friction

ABSTRACT

This specification describes a method for reducing kinetic friction by means of profiled surface patterns when devices and appliances of different materials, sizes and shapes are in contact with air, gas and liquid masses. The method can be used above all to achieve savings in energy consumption in means of transport by providing their surfaces with profiled surface patterns. The method is also suited for use in numerous other applications where kinetic friction between the aforesaid masses and devices and appliances is to be reduced for a specific reason, but those are not covered by the scope of this application.

The aim of the present invention is to reduce kinetic friction in caseswhere devices and appliances of different materials, sizes and shapes asdescribed later on are in contact with air, gas or liquid masses, whereeither the said masses are moving in relation to the said devices andappliances or the said devices and appliances are moving in the saidmasses, on the surface of a mass, e.g. in a liquid.

Kinetic frictional resistance can be reduced by providing the surfacesof devices and appliances with profiled surface patterns adapted to thesize and shape of the devices and appliances in question. The profiledsurface patterns may consist of either engraved or raised surfacepatterns. The size and shape of the pits and bulges are determinedaccording to the size and shape of the devices and appliances. Insymmetrical devices and appliances, such as e.g. gently arched surfaces,they may have an identical regular shape, such as a spherical calotte,which may be either a pit or a bulge. More sharply bent surfaces requiresmaller pits or bulges than in the above-mentioned case.

The pit or bulge may also have a shape other than spherical calotte,different rounded shapes of a truncated cone, and resembling the shapeof the edge of an oval or closed shell. It would be possible to make analmost unlimited number of different shapes of these pits or bulges, butwould it be sensible except as a way of sidestepping the idea, space thesimplest shape is surely the best solution. The aim is not to obtain apatent on pits and bulges of different sizes and shapes, but on ways inwhich these can be used methodically to reduce kinetic friction in thesedevices and appliances described here, which at present are known ascompletely smooth-simplified objects.

The reduction of kinetic friction in this manner is based on a physicalphenomenon that has been known at least since the 19^(th) century. Agood example is the golf ball, which was patented already about ahundred years ago. A golf ball with a profiled surface flies to adistance of about 230 m, whereas a smooth surfaced golf ball flies onlyabout 90 m, so the difference factor is about 2½. Holding the ball inthe hand, it seems that the profiled surface is of little consequence,but its effect is of a magnificent order. The reduction of airresistance by a factor of about 2.5 is such a great achievement that itis advisable to apply this phenomenon on a large scale to other devicesand appliances as well. It is true that this phenomenon has been appliedin a few other devices and appliances besides balls, including the golfball. These are U.S. Pat. No. 4,973,048 (A 63 B 65/00)=Nemeth's javelin.U.S. Pat. No. 284 302 (B 64 C 1/38)=Transversely fluted automobile. U.S.Pat. No. 5,289,997 (B 64 C 1/38)=Flat rear surfaces, truck, motor boatand gun bullet. U.S. Pat. No. 1,864,803=Splined propeller. As far as weknow, none of these devices and appliances have been taken intoindustrial production, at least not in any significant degree. Otherwisethey would be in everyday use around the world.

It is known that a roughness of the surface of a device or applianceproduces a physical effect when the surface meets a flow. The roughnessof the surface disrupts the flow and reduces friction. The shape andsize of the roughness have different effects on the reduction of kineticfriction. If the rough profiled pattern is too unsubstantial, its,effect is likewise unsubstantial. If the rough profiled pattern is toolarge, then the effect is to the contrary, in other words, it increasesthe kinetic friction. An optimum size and has been found in the golfball, but this size and shape can not be exclusively used in all thesedevices and appliances to be presented here because they differ from thegolf ball in respect of shape and size. The golf ball is only an exampleof how this physical phenomenon should be applied to other devices andappliances as well.

Shuttle and wedge shaped devices and appliances tailor made to reducekinetic friction. In these, too, surfaces with profiled patterns reducefriction as compared to a smooth surface because in any case the largestcross-section of the device or appliance forms a plane that offers thegreatest resistance to motion.

As the devices and appliances differ from each other already because oftheir size and shape, it is hardly possible to enhance the performanceby a factor of about 2.5 in all the cases in which this method isapplied. At low speeds, the advantage will be small, if at allmeasurable, regardless of the nature of the device or appliance. Athigher speeds, an advantage is always achieved. Even a slightimprovement in the performance is worth while because the amount ofmaterials to be modified remains almost unchanged. The only additionalcosts arise from the tools, but in large series their cost will bealmost nil.

The devices and appliance may move or be stationary against the flow atan oblique angle, in which case there arises a slip angle. Therefore,the side surfaces have to be profiled as well to reduce the slipcomponent.

The profiled patterns also stiffen the structure of the devices andappliances. Whether this is an advantage or a drawback depends on theintended use. An advantage may be achieved due to the reduction inmaterial thickness especially in plate structures. In the case ofelastic materials, it may even constitute a drawback as it hindersadaptation.

Nature provides a model example of profiling. There is at least one seaanimal that has a head with a bump profile, viz. the humpback whale. Thehumpback whale makes a round trip from one polar region to the otherevery year, the distance even in one direction being thousands ofkilometers. The tubercles on the head of the whale are surely notuseless, but they help serve energy during the long swim. The head withtubercles on it breaks the bonds of water and makes swimming easier. Nodoubt nature would not have prepared hindrances to such a great effort.

Another example found in nature is the crocodile. It has an armor-likeskin protecting it against injury, but the skin also has many bumps onit, and surely not without purpose. As we know, the animal is very gawkyand normally would not be able to catch any prey, but in the course ofmillions of years it has developed an effective method of preying. Itlies in ambush near the water's edge at the shore, waiting for preyanimals coming to drink, with only its eyes and nostrils above the watersurface. When a suitable chance appears, it attacks the prey animal andoften manages to kill the prey. In this case, too, the bumpy skin breaksthe bonds of water, permitting a faster attack while at the same timecontributing towards preserving the species.

It is unimportant how the driving force acting on the devices andappliances is generated, either by an impact or by applying a continuousdriving force to them.

The details of the features of the solution of the invention arepresented in the claims below.

In the following, the invention will be described in detail withreference to the attached drawings, wherein FIGS. 1-15 present preferredembodiments of the solution of the invention, showing a number ofdevices and appliances so far known as smooth-surfaced ones but whichcan be provided with pattern profiled surfaces to save energy andincrease the speed and range:

-   -   Automobiles 1, 2, all types covered by this designation.        Examples are given here only in FIG. 1 and 2, because in all        other versions the same principle is applied.    -   Trains 11, all types covered by this designation, a locomotive        being shown as an example in FIG. 11.    -   Trailed vehicles, such as trailers.    -   Vehicle top boxes 7. FIG. 7.    -   Motor cycles 5, FIG. 5. Motor sledges and buggies.    -   Airplanes 3, FIG. 3. Airships, helicopters, sailplanes and other        flying devices, such as flying models and comparable devices.    -   Rockets and missiles. FIG. 15.    -   Projectiles 14, grenades and aerial bombs. FIG. 14.    -   Bullets and shots 12, 13. FIGS. 12 and 13.    -   Ships 8, all types covered by this designation. As an example,        FIG. 8 shows a drawing of the bow of a vessel. The bulge of        ships can be implemented as a vibrating structure, which will be        better able to break the bonds of water than a solid structure.        As an alternative, a more elongated structure could be used        instead of a point-form structure like this. Such a structure        would have a more extensive effect on breaking the bonds of        water, extending deeper to the bottom part of the prow. Such a        device could be separate structure attachable to the bow part of        the ship and not necessarily a fixed structure. An        interchangeable part. In long vessels, the effect of the        profiling of the rear part after the largest sectional plane        decreases, but still it does not have an adverse effect, either.        A computer model produces such a result. No practical        experiments with a prototype have been carried out. In vessels        with commander's cabins and engine spaces in the rear part, the        profiling may extend over the entire vessel.    -   Motor boats 8, 10, FIGS. 9 and 10. Water-jet-powered boats,        water scoters, canoes, boats, hovercraft.    -   Submarines and torpedoes.

In the case of devices and appliances for which a good, undisturbed andperfect field of vision is important for reasons of controllability orother factors, the profiling of transparent surfaces should be omittedwhere profiling would obscure or distort the field of vision.

The surface pattern profiling also works in closed spaces, such aspiping. It is unimportant which is moving, the aforesaid masses or thedevices and appliances, with respect to each other. The final result isthe same. The inner surfaces of pipes are provided with profiled surfacepatterns in the same way as the outer surfaces of the devices andappliances listed above. The applications include various pipinginstallations, such as oil and gas pipes, air conditioning, water andsewage pipes. The first-mentioned of these may be hundreds of kilometerslong, so pumping energy would be saved due to lower pipe losses.Moreover, intermediate pumping stations could be located at longerdistances between them. The feed channels of the turbines ofhydroelectric power stations as well as the feed pipes with a large headof fall used to supply pipe-fed turbines can be provided with profiledsurface patterns, which will increase the power output because the flowresistance decreases. The intake and exhaust manifolds as well asexhaust pipes of combustion engines can be provided with internalprofiled surface patterns, which would improve the breathing capacity ofthe engines and increase their power output.

Fixed structures subject to stress from strong winds, water currents andwaves should be provided with profiled surface patterns to reduce thestress if necessary to improve durability or performance. Severalexamples can be found, such as the towers of wind power plants, thepylons and conductors of power transmission lines, underwater and otherstructures of bridge piers if their performance is to be improved, andtall and round TV towers.

Sportsgear and sportswear can be provided with profiled surfacepatterns, but this probably requires some changes in the rules. Inthrowing sports, the javelins, shots, hammers, discs etc., if it isdesired that they fly farther than the earlier smooth-surfaced models.The following sportswear could be provided with profiled surfacepatterns, which would reduce the kinetic friction of air flow more orless, depending on the case and the speed used, as compared tosmooth-surfaced sportswear:

-   -   Full-length competition wear 6, FIG. 6. Ski jumping, fast        downhill skiing, slalom, skating and skiing.    -   Helmets, FIG. 6. Gauntlets, the shoe part of skates, jumping        shoes, spikes, gym shoes and masks.    -   Goggles and visors only as far as the surface patterns do not        obstruct visibility.    -   Partially close-fitting sportswear, such as in rowing the person        sits with his/her back facing the direction of advance, the back        thus dividing the air flow, so the person has to wear a jumper        on his/her upper body (the shanks of the oars also have to be        profiled).    -   In other sports the trouser part as well.    -   Attachable number tags, advertisements and vests also have to be        profiled.

In motor sports, all types of racing cars should be provided withprofiled surface patterns covering the vehicle almost completely, maybethe ailerons only partially. Likewise, the inner surfaces of the intakeand exhaust manifolds and exhaust pipes and air inlet ports of theengines, and even the sides of the tires, because when the vehicle isrunning along a gentle curve the side of the car is moving obliquely inthe direction of advance, and so are the tires. Projecting parts such asmirrors and handrails etc. should be profiled as well.

In motor cycle sports, about the same measures as in the case of cars,with the addition of the plexiglass and driver's overalls, FIGS. 5 and6. To be profiled as well. In motor boat sports, FIG. 10, about the samemeasures apply as above, but additionally the bottom part should beprofiled. In the case of waterjet-powered boats, additionally the waterinlet and exhaust channels should be profiled.

The cigar-shaped bodies of ice chute toboggans and competition wear tobe profiled as well.

The profiled surface patterns can be made in many ways, but alwaysadapted in relation to the shape and size of the devices and appliances.Plate-like pieces needed in the devices and appliances can be providedwith profiled surface patterns already during the rolling and pressingstage. In the case of thick bodies, in connection with casting and otherworking. In the case of garments, in connection with weaving and otherproduction processes. It is also possible to attach a previouslyprofiled separate surface to a ready-made device or appliance bywelding, gluing, riveting, screwing, vulcanizing or by similartraditional methods. If necessary, the traditional shapes of devices andappliances can be reshaped to gain the best benefit. Perhaps the trendis now increasingly towards round and curved shapes. Devices andappliances already in use can be renewed by only reshaping the surfaceparts. In this presentation, the number of figures in the drawings hasbeen limited to 15 because their number would be too large if all thedifferent versions were to be illustrated.

Anyway, the drawings reveal the principle of how the method should beapplied in the case of different devices and appliances.

The shapes and sizes of the profiled patterns 16 can not be accuratelydefined because the devices and appliances are different in relation toeach other. In principle, there might be an almost unlimited number ofsizes and shapes of patterns, and therefore only the method or means ispatented, i.e. the way in which profiling can be used in the devices andappliances mentioned here to reduce kinetic friction as compared withsmooth-surfaced devices and appliances.

1. A method for reducing kinetic friction, characterized in that devicesand appliances (1-15) of different materials, sizes and shapes areprovided with profiled surface patterns to reduce kinetic friction whenthe said devices and appliances are in contact with air, gas or liquidmasses.
 2. A method according to claim 1, characterized in that thesurfaces of the devices and appliances of different materials, sizes andshapes are profiled with differently sized sunken or raised patterns orwith combinations of such patterns, or even helical patterns, whereinthe surfaces profiled with sunken and raised patterns may be the shapeof a spherical calotte or truncated cone or imitations of these shapesand/or imitations of polygonal, roundish or oval shapes, or resemblingthe shape of the edge of a closed shell and the bumped bulges in themidpart of a crocodile's back.
 3. A method according to claim 1,characterized in that the devices and appliances of different materials,sizes and shapes are provided with profiled surface patterns adapted inrelation to their intrinsic size and shape so that the size and shape ofthe pattern may vary in a way best suited to the devices and appliancesin each case. They may even be partial.
 4. Means for reducing kineticfriction, characterized in that devices and appliances (1-15) ofdifferent materials, sizes and shapes are provided with profiled surfacepatterns to reduce kinetic friction when the said devices and appliancesare in contact with air, gas or liquid masses, comprising for examplethe following devices and appliances, which at present are known asbeing completely smooth-surfaced: Automobiles (1, 2), and all otherscovered by this designation. Trains (11), and all devices covered bythis designation. Trailed vehicles, such as trailers and vehicle topboxes (7). Motor cycles (5). Motor sledges and buggies. Airplanes (3).Helicopters, airships and other flying devices, such as sail-planes andflying models. Rockets and missiles (15). Projectiles, grenades andaerial bombs (14). Bullets and shots (12 and 13). Ships (8), and alldevices covered by this designation, preferably also the above-water andunderwater parts, such as implementing the bulge as a vibrating andlarger structure. Motor boats (9 and 10). Water-jet-powered boats, waterscoters, canoes, boats, sailboats and hovercraft. Above-water andunderwater parts as well. Submarines and torpedoes. Surfing boards. 5.Means according to claim 4, comprising the following devices andappliances of a closed nature, such as various piping installations,which are at present known as having completely smooth inner surfaces:Oil and gas pipes (4). Air conditioning, water and sewage pipes. Feedchannels and throats of turbines in hydropower plants. Feed pipes with alarge head of fall used to supply pipe-fed turbines. Intake and exhaustchannels and manifolds, exhaust pipes (4) and air inlet ports andchannels of combustion engines.
 6. Means according to claim 4,characterized in that they comprise the following fixed structures,which at present are known as completely smooth-surfaced structures,such as: Rotor towers of wind power plants, tall and round TVmasts/towers. Pylons and conductors used in the transmission of electricpower. Those parts of bridge piers that are in contact with water. Allother structures that can be profiled if the structure permits and ifnecessary for protection or performance, to reduce the effect of strongwinds or water currents or waves. E.g. gas or oil drillingplatforms/production platforms.
 7. Means according to claim 4,characterized in that they comprise those parts of devices andappliances that are supposed to be transparent, which at present areknown as being always completely smooth-surfaced, such as: Windshieldsand rear windows of vehicles. Protective goggles and visors as personalequipment. Windows and protective hoods in different means of transport.Protective hoods of vehicle lamps as far as no obstruction toillumination arises. The profiling has to be carried out in such mannerthat it does not obstruct the field of vision.
 8. Means according toclaim 4, characterized in that they comprise the following sports gearand garments, which at present are known as being completelysmooth-surfaced, such as: Full-length competition wear (6). Ski jumping,fast downhill skiing, slalom, skating and skiing. Helmets, gauntlets,(6), the shoe part of skates, jumping shoes, spikes, gym shoes andmasks. Rowing jumpers. (The shanks of oars to be profiled as well.)Trousers and jumper combinations. Attachable number tags, advertisementsand vests.
 9. Means according to claim 4, characterized in that theycomprise devices and appliances used in motor sports, which at presentare known as being completely smooth-surfaced, such as: Body parts ofautomobiles (1 and 2), ailerons, mirrors, intake and exhaust manifoldsof engines, exhaust pipes, air intake ports, projecting handrails andsides of tires. Surface parts of motor cycles, plexiglass shields,driver's overalls, helmet, intake and exhaust manifolds of the engine,exhaust pipes, brace rods and visor. FIGS. 5 and 6, as well as motorsledges and buggies, profiling of surface parts as far as possible. Atpresent they are known as being completely smooth-surfaced. For theengines, the same measures as for those above, and also surfaceprofiling of ice chute toboggans and competition wear. At present, theseare known as being completely smooth-surfaced.
 10. Means according toclaim 4, characterized in that they comprise the profiling of athleticsgear, such as javelins, discs, hammers and shots. At present, these areknown as being completely smooth-surfaced.
 11. Means according to claim4, characterized in that they also comprise a warning about profiling oftransparent surfaces if the profiling is so implemented that the patterncould produce a burning lens effect when exposed to sun beams. This canbe prevented by changing the profiling patterns or by moving the heatsensitive surface farther away.